Field of the Invention
The present invention relates to a Wireless Local Area Network (WLAN), and more particularly, to a Physical layer Protocol Data Unit (PPDU) format to which Space-Time Block Coding (STBC) is applied in a High Efficiency WLAN (HEW), a transmitting method, receiving method, transmitting apparatus, receiving apparatus, and software using the PPDU format, and a recording medium that stores the software.
Discussion of the Related Art
Along with the recent development of information and telecommunication technology, various wireless communication techniques have been developed. Among them, the WLAN enables a user to wirelessly access the Internet based on radio frequency technology in a home, an office, or a specific service area using a portable terminal such as a Personal Digital Assistant (PDA), a laptop computer, a Portable Multimedia Player (PMP), a smartphone, etc.
To overcome limitations in communication speed that the WLAN faces, the recent technical standards have introduced a system that increases the speed, reliability, and coverage of a wireless network. For example, the Institute of Electrical and Electronics Engineers (IEEE) 802.11n standard has introduced Multiple Input Multiple Output (MIMO) that is implemented using multiple antennas at both a transmitter and a receiver in order to support High Throughput (HT) at a data processing rate of up to 540 Mbps, minimize transmission errors, and optimize data rates.
As more and more devices such as smartphones have recently supported WLAN, more Access Points (APs) have been deployed to support this trend. Although WLAN devices with high performance conforming to the Institute of Electrical and Electronics Engineers (IEEE) 802.11ac standard are used more than legacy WLAN devices conforming to the IEEE 802.11g/n standard, a WLAN system having higher performance is required due to WLAN device users' increased use of large-capacity content such as an Ultra High Definition (UHD) video. A legacy WLAN system seeks to increase a bandwidth and a peak transmission rate, only to fail to increase performance that users actually feel.
HEW standardization is under discussion in a so-called IEEE 80.111x task group. The HEW aims to increase performance felt by users demanding large-capacity, high-rate services, while supporting simultaneous access of many Stations (STAs) in an environment in which a plurality of APs are densely deployed and the coverage of APs is overlapped.
However, there is no specified method for configuring a PPDU format to STBC is applied in a HEW.